I have collected a number of film holders here and discovered that older wooden holders are generally about .005" "deeper". I have one that came loaded with old Ansco film and had a paper sheet underneath.

Using a micrometer on my Tachihara back, the ground glass position is nearly ide ntical to the older wooden holders. When I calibrate the depth of the glass, put in a wooden holder, the depth is within a few thou. The plastic holders are abo ut .005" too close.

What gives? are the newer holders made for thinner films?